The present disclosure relates generally to digital-to-analog converters, and more particularly, to a method and system for reducing or eliminating transient (POP) noise created when a communication instrument or sound broadcasting system is powered on or off.
A typical sound broadcasting system contains an audio amplifier circuit that drives a broadcasting module such as a speaker. During the power-up or power-down phases of an audio amplifier circuit's operation, an abrupt change in the amplifier's output voltage can result in an undesirable POP noise. The POP noise has always been a major issue for any communication devices or systems that use amplifier circuit. These devices can be a mobile phone, home stereo, or any other sound broadcasting instruments that include speaker or microphone. Transient noises can occur during power-up and/or power-down sequences for a device producing a pop or click noise. These undesired noises can be extremely irritating to users and damaging to the device as well. It is of the best interest to provide a solution to eliminate or reduce such noises.
The current available solutions to the problem often require large and expensive parts such as large capacitors and external pads. These capacitors are often large and require an external pin for connection to integrated circuits. Due to this issue, the size and cost of such circuits can increase greatly. While these existing solutions do reduce or prevent POP noise from occurring, there are still needs for simpler and lower cost solutions. Since technology, such as software and microprocessors, continues to grow, cost for implementing such technology to solve the problem of POP noise may be lowered.
It is always desirable for additional flexible and low cost designs that provide the reduction or elimination of POP noises.